Employee Benefits - Narrative (Details) - USD ($)			3 Months Ended		12 Months Ended
	Jul. 09, 2012	Jan. 02, 2012	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Compensation and Retirement Disclosure [Abstract]
Number of hours of service required for participation in ESOP, per first 12 month period (in hours)		1000 hours
Vesting percentage after requisite service period is met (as a percent)		100.00%
Requisite service period (in years)		2 years
Employee stock ownership plan (ESOP), requisite service period and 12 months		1000 hours
Employee stock ownership plan (ESOP), debt structure, employer loan, amount	$ 2,600,000
Employee stock ownership plan shares purchased	259,210
Employee stock ownership plan (ESOP), weighted average purchase price of shares purchased (in dollars per share)	$ 10.17
Amortization period of ESOP loan	10 years
Employee stock ownership plan (ESOP), debt structure, employer loan, interest rate	2.30%
Employee stock ownership plan (ESOP), periodic installment payments from esop, amount paid					$ 269,000
Employee stock ownership plan (ESOP), interest payments from esop					$ 26,000
ESOP compensation expense for allocated shares			$ 321,000	$ 359,000